CHADS2 score: Difference between revisions
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| [[International normalized ratio|INR]] to 2.0-3.0, unless contraindicated (e.g. clinically significant GI bleeding, inability to obtain regular INR screening) | | [[International normalized ratio|INR]] to 2.0-3.0, unless contraindicated (e.g. clinically significant GI bleeding, inability to obtain regular INR screening) | ||
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The following treatment strategies were recommended in the table | The following treatment strategies were recommended in the table entitled Anticoagulation based on the CHADS2 score:<ref name="pmid15477396 " /><ref name=Gage2001 /> | ||
For detailed recommendations on how the treatment recommendations based on the CHADS<sub>2</sub> score are modified by considering additional 'stroke risk modifier' risk factors using the CHA2DS2-VASc score, see [http://www.escardio.org/guidelines-surveys/esc-guidelines/Pages/atrial-fibrillation.aspx ESC guideline] recommendations. | For detailed recommendations on how the treatment recommendations based on the CHADS<sub>2</sub> score are modified by considering additional 'stroke risk modifier' risk factors using the CHA2DS2-VASc score, see [http://www.escardio.org/guidelines-surveys/esc-guidelines/Pages/atrial-fibrillation.aspx ESC guideline] recommendations. | ||
Revision as of 18:37, 26 November 2010
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| Condition | Points | |
|---|---|---|
| C | Congestive heart failure | |
| H | Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication) | |
| A | Age >/=75 years | |
| D | Diabetes Mellitus | |
| S2 | Prior Stroke or TIA |
CHADS score or CHADS2 score is a clinical prediction rule for estimating the risk of stroke in patients with non-rheumatic atrial fibrillation (AF), a common and serious heart arrhythmia associated with thromboembolic stroke. It is used to determine whether or not treatment is required with anticoagulation therapy or antiplatelet therapy,[1] since AF can cause stasis of blood in the upper heart chambers, leading to the formation of a mural thrombus that can dislodge into the blood flow, reach the brain, cut off blood supply to the brain, and cause a stroke. A high CHADS2 score corresponds to a greater risk of stroke, while a low CHADS2 score corresponds to a lower risk of stroke. The CHADS2 score was validated by a study of nonrheumatic atrial fibrillation patients aged 65 to 95 who were not prescribed the anticoagulant warfarin.[2]
Method
The CHADS2 scoring table is shown above:[3]
Adding together the points that correspond to the conditions that a patient has will result in the CHADS2
score. This score is used in the next section to estimate stroke risk.
Risk of stroke
| CHADS2 Score | Stroke Risk % | 95% CI |
|---|---|---|
According to the findings of the validation study, the risk of stroke as a percentage per year is shown in the table titled Annual Stroke Risk:
While the CHADS2 score provides prognostic information regarding the natural history of non-valvular atrial fibrillation (NVAF) in the absence of warfarin therapy, it should be noted that warfarin therapy also has an associated stroke risk[4] (particularly hemorrhagic stroke) and a risk of major bleeding, and these considerations were taken into account in the development of the recommendations in the next section.
The CHADS2 score has various limitations, which have been debated [5]. Notably, many stroke risk factors have not been included, and whilst simple, the score has only modest predictive value for thromboembolism.
In order to improve upon the prognostic utility of the CHADS2 score and to incorporate additional stroke risk factors, the CHA2DS2-VASc score has been proposed [6]. These additional 'clinically relevant non-major' stroke risk factors include age 65-74, female gender and vascular disease. In the CHA2DS2-VASc score, 'age 75 and above' also has extra weight, with 2 points.
The CHA2DS2-VASc score has been used in the new European Society of Cardiology guidelines for the management of atrial fibrillation [7].
The European Society of Cardiology (ESC) guidelines recommend that if the patient has a CHADS2 score of 2 and above, oral anticoagulation (OAC) therapy is recommended. OAC options include warfarin with an INR target of 2-3 or dabigatran.
If the CHADS2 score is 0-1, other stroke risk modifiers should be considered: (i) If there are 2 or more risk factors (essentially a CHA2DS2-VASc score score of 2 or more), OAC is recommended; and (ii) If there is 1 risk factor (essentially a CHA2DS2-VASc score score=1), then antithrombotic therapy with either OAC or aspirin (OAC preferred) is recommended.
If patients have a CHA2DS2-VASc score of 0, then such patients are ‘truly low risk’[8]. The ESC guidelines recommend either aspirin or no antithrombotic therapy, but 'no antithrombotic therapy' is preferred[9].
Anticoagulation based on the CHADS2 score
| Score | Risk | Anticoagulation Therapy | Considerations |
|---|---|---|---|
| 0 | Low | Aspirin | Aspirin daily |
| 1 | Moderate | Aspirin or Warfarin | Aspirin daily or INR to 2.0-3.0, depending on factors such as patient preference |
| 2 or greater | Moderate or High | Warfarin | INR to 2.0-3.0, unless contraindicated (e.g. clinically significant GI bleeding, inability to obtain regular INR screening) |
The following treatment strategies were recommended in the table entitled Anticoagulation based on the CHADS2 score:[1][2]
For detailed recommendations on how the treatment recommendations based on the CHADS2 score are modified by considering additional 'stroke risk modifier' risk factors using the CHA2DS2-VASc score, see ESC guideline recommendations.
References
- ↑ 1.0 1.1 Gage BF, van Walraven C, Pearce L; et al. (2004). "Selecting patients with atrial fibrillation for anticoagulation: stroke risk stratification in patients taking aspirin". Circulation. 110 (16): 2287&ndash, 92. doi:10.1161/01.CIR.0000145172.55640.93. PMID 15477396.
- ↑ 2.0 2.1 2.2 Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ (2001). "Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation". JAMA. 285 (22): 2864–70. PMID 11401607.
- ↑ "Risk of Stroke with AF". VA Palo Alto Medical Center and at Stanford University: the Sportsmedicine Program and the Cardiomyopathy Clinic. Retrieved 2007-09-14.
- ↑ Steiner, Thorsten (2006). "Intracerebral hemorrhage associated with oral anticoagulant therapy: current practices and unresolved questions". Stroke. 37 (1): 256–62. PMID 16339459 doi:10.1161/01.STR.0000196989.09900.f8. Unknown parameter
|coauthors=ignored (help) - ↑ Karthikeyan G, Eikelboom JW. The CHADS2 score for stroke risk stratification in atrial fibrillation--friend or foe? Thromb Haemost. 2010 Jul 5;104(1):45-8.
- ↑ Lip GY, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation. Chest. 2010 Feb;137(2):263-72.
- ↑ European Heart Rhythm Association; European Association for Cardio-Thoracic Surgery, Camm AJ, Kirchhof P, Lip GY, Schotten U, Savelieva I, Ernst S, Van Gelder IC, Al-Attar N, Hindricks G, Prendergast B, Heidbuchel H, Alfieri O, Angelini A, Atar D, Colonna P, De Caterina R, De Sutter J, Goette A, Gorenek B, Heldal M, Hohloser SH, Kolh P, Le Heuzey JY, Ponikowski P, Rutten FH. Guidelines for the management of atrial fibrillation: the Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC). Eur Heart J. 2010 Oct;31(19):2369-429.
- ↑ Van Staa TP, Setakis E, Di Tanna GL, Lane DA, Lip GY. A comparison of risk stratification schema for stroke in 79884 atrial fibrillation patients in general practice. J Thromb Haemost. 2010 Oct 1. doi: 10.1111/j.1538-7836.2010.04085.x. [Epub ahead of print] PubMed PMID: 21029359.
- ↑ Lip GY, Halperin JL. Improving stroke risk stratification in atrial fibrillation. Am J Med. 2010 Jun;123(6):484-8.